Various processes exist to monitor physiological characteristics of a patient. For example, capnography is the monitoring of the concentration or partial pressure of carbon dioxide (CO2) during a respiratory cycle. Its main development has been as a monitoring tool for use during anesthesia and intensive care. A graphical representation of a patient's ventilatory status for CO2 concentration can be presented as a capnograph or capnogram, illustrating expiratory CO2 concentration plotted against time or expired volume. The capnogram is a direct monitor of the inhaled and exhaled concentration or partial pressure of CO2 and an indirect monitor of the CO2 partial pressure in the arterial blood.
Chronic obstructive pulmonary disease (COPD) refers to chronic bronchitis and emphysema, two commonly co-existing diseases of the lungs in which the airways become narrowed. This condition leads to a limitation of the flow of air to and from the lungs causing shortness of breath. The limitation of airflow is normally irreversible and usually gets progressively worse over time.
Typically, a healthcare provider can look at the capnogram displayed on a monitor and interpret it by visual inspection. Visual evaluation and interpretation of the capnogram is typically done by qualitative pattern recognition. Pattern recognition is a technique in which a capnogram is visually compared to a set of abnormal capnograms, with a corresponding differential diagnosis for each abnormal shape. This process requires considerable skill and specialized knowledge on the part of the person doing the visual comparison and is useful only for conditions or diseases that result in a large-scale abnormality in capnogram shape that is clearly visible to the naked eye. Moreover, experts are predicting a shortage of qualified medical personnel in the future in view of continued population growth and greater access to healthcare.